어음역동범위(speech dynamic range)는 주파수별 어음 에너 지 분포 중 최대 레벨(maximum levels)과 최소 레벨(minimum levels) 사이를 의미하며 어음인지도 수행력(speech intelligibility performance)에 있어 중요한 역할을 한다(Jin et al., 2014; Moore, 2006). 예를 들어, 스피치 맵핑(speech mapping)과 같 은 실이측정(real ear measurement) 시에 입력 음압에 따른 어 음역동범위와 대상자의 청력역치 레벨 간의 관계를 통해서 보 청기 적합의 결과를 예측할 수 있다(Moore, 2006). 만약 어음 인지도를 저해하는 요소(예: 소음 등)가 없다는 가정하에 한 사 람의 청력역치 레벨이 모든 주파수 영역에서 어음의 역동범위 보다 좋다면, 100% 청취가 가능함을 의미한다. 반대로 한 사람 의 청력역치 레벨이 모든 주파수 영역에서 어음의 역동범위보다 나쁘다면, 어떠한 말소리도 들을 수 없어 말소리 청취도가 0%임 을 의미한다. 이렇듯 어음역동범위는 어음인지도 수행력의 결정 에 중요한 역할을 한다.
Purpose: Dynamic range (DR) of speech refers to the minimum and maximum levels of speech across frequencies and it depends on language. Recent findings showed that Korean speech DR is different from the DRs of other languages such as English and Mandarin. The purpose of this study was to identify the characteristics of Korean speech DR according to frequency (21 bands), gender (male and female), and speech type [words, sentences, and continuous discourses (CDs)]. Methods: DRs for 70 participants were recorded and yielded using cumulative histogram levels. Then, the DRs were compared according to frequency bands, gender, and speech type after level normalization at 65 dB sound pressure level. Results: Although there were no statistical differences between DRs for sentences and CDs, DRs for words were wider than DRs for other speech types. In terms of gender, DRs for female speakers were wider than DRs for male speakers in all speech types except a few frequency bands. Conclusion: Speech DR is important in real ear measurements like speech mapping because audibility can be determined based on the relationship between a person’s hearing thresholds and the DR of speech. Thus, the results of this study contribute to more accurate hearing aid fitting according to frequency bands, gender, and speech type for Korean listeners.
INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSIONS REFERENCES
